Estimation of Genetic Parameters and Correlation between Yearling Ultrasound Measurements and Carcass Traits in Hanwoo Cattle

Association of R3HDM1 variants with growth and meat quality traits in Qinchuan cattle and its role in lipid accumulation

The R3H domain containing 1 (R3HDM1) gene has emerged as a candidate influencing residual feed intake and beef yield. Despite this, the genetic variation of R3HDM1 and its effects on beef cattle remain unexplored. This study identified four single nucleotide polymorphisms (SNPs) in the R3HDM1 gene of Qinchuan cattle, with the g.61695680 T > C SNP significantly associated with chest depth and backfat thickness. The g.61695680 T > C synonymous mutation significantly altered the RNA secondary structure and stability of R3HDM1. RNA interference experiments demonstrated that R3HDM1 knockdown reduced adipogenesis and lipid accumulation in bovine preadipocytes by modulating key adipogenic factors such as CEBPβ (P < 0.05), ACCα (P < 0.05), and ATGL (P < 0.01). These findings suggest that the g.61695680 T > C variants within R3HDM1 could serve as valuable molecular markers for selecting improved Qinchuan cattle, thus enhancing genetic selection strategies for beef production.

Changes in Gut Microbiota in Peruvian Cattle Genetic Nucleus by Breed and Correlations with Beef Quality

This study evaluated the gut microbiota and meat quality traits in 11 healthy female cattle from the Huaral region of Peru, including 5 Angus, 3 Braunvieh, and 3 F1 Simmental × Braunvieh. All cattle were 18 months old and maintained on a consistent lifelong diet. Meat quality traits, including loin area, fat thickness, muscle depth, and marbling, were assessed in vivo using ultrasonography. Fecal samples were collected for microbiota analysis, and DNA was extracted for 16S and 18S rRNA sequencing to characterize bacterial, fungal, and protist communities. Significant correlations were observed between microbial genera and meat traits: Christensenellaceae R-7 and Alistipes were positively associated with marbling and muscle area, while Rikenellaceae RC9 showed a negative correlation with fat thickness. Among fungi, Candida positively correlated with marbling, while Trichosporon was negatively associated with muscle depth. For protists, Entodinium negatively correlated with fat thickness and marbling. Alpha diversity varied by breed, with Angus showing greater bacterial diversity, and beta diversity analyses indicated a strong breed influence on microbial composition. These findings suggest that microbial composition, shaped by breed and dietary consistency, could serve as an indicator of meat quality, offering insights into gut microbiota's role in optimizing cattle production.

Image analysis traits of multiple muscles and intermuscular/subcutaneous fat influence Japanese Black beef carcass price and genetic parameters

OBJECTIVE

The purposes of this study were to investigate the relationship between carcass unit price per 1 kg (UP) and multiple muscles and intermuscular fat (IF)/subcutaneous fat of beef carcasses using image analysis of cross-section images for Wagyu beef cattle in Japan, and to estimate their genetic parameters.

METHODS

The carcasses used in this study were 1,807 Japanese Black (Wagyu) cattle (1,216 steers and 591 heifers). An analysis of variance was conducted with UP as the dependent variable and market date, age in months, sex, and image analysis traits (IAT) as fixed effects, and standard partial regression coefficients were calculated for each IAT on UP. Also, the heritability of each IAT that affected UP and genetic correlation among IAT vs carcass grading traits were estimated.

RESULTS

Not only IAT related to carcass grading traits, M. trapezius dorsi, M. latissimus dorsi, and IF traits were significant differences in UP (p<0.05). The heritability of IAT associated with UP was estimated at 0.38 to 0.85. The genetic correlations between the area and thickness of M. trapezius dorsi and M. latissimus dorsi vs rib eye area (REA) were estimated to be moderately positive (0.53 to 0.66), while the genetic correlations between the IF area percentage vs carcass weight, REA, and yield score were estimated to be negative (-0.40, -0.56, and -0.34).

CONCLUSION

UP was influenced by various traits, including M. trapezius dorsi, M. latissimus dorsi, and IF traits, as well as image analysis associated with carcass grading traits. Since these IAT associated with UP had hereditary and desirable genetic correlations with carcass grading traits, these traits were also important for genetic improvement.

Estimation of genetic correlations and genomic prediction accuracy for reproductive and carcass traits in Hanwoo cows

This study estimated the heritabilities (h2) and genetic and phenotypic correlations between reproductive traits, including calving interval (CI), age at first calving (AFC), gestation length (GL), number of artificial inseminations per conception (NAIPC), and carcass traits, including carcass weight (CWT), eye muscle area (EMA), backfat thickness (BF), and marbling score (MS) in Korean Hanwoo cows. In addition, the accuracy of genomic predictions of breeding values was evaluated by applying the genomic best linear unbiased prediction (GBLUP) and the weighted GBLUP (WGBLUP) method. The phenotypic data for reproductive and carcass traits were collected from 1,544 Hanwoo cows, and all animals were genotyped using Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The genetic parameters were estimated using a multi-trait animal model using the MTG2 program. The estimated h2 for CI, AFC, GL, NAIPC, CWT, EMA, BF, and MS were 0.10, 0.13, 0.17, 0.11, 0.37, 0.35, 0.27, and 0.45, respectively, according to the GBLUP model. The GBLUP accuracy estimates ranged from 0.51 to 0.74, while the WGBLUP accuracy estimates for the traits under study ranged from 0.51 to 0.79. Strong and favorable genetic correlations were observed between GL and NAIPC (0.61), CWT and EMA (0.60), NAIPC and CWT (0.49), AFC and CWT (0.48), CI and GL (0.36), BF and MS (0.35), NAIPC and EMA (0.35), CI and BF (0.30), EMA and MS (0.28), CI and AFC (0.26), AFC and EMA (0.24), and AFC and BF (0.21). The present study identified low to moderate positive genetic correlations between reproductive and CWT traits, suggesting that a heavier body weight may lead to a longer CI, AFC, GL, and NAIPC. The moderately positive genetic correlation between CWT and AFC, and NAIPC, with a phenotypic correlation of nearly zero, suggesting that the genotype-environment interactions are more likely to be responsible for the phenotypic manifestation of these traits. As a result, the inclusion of these traits by breeders as selection criteria may present a good opportunity for developing a selection index to increase the response to the selection and identification of candidate animals, which can result in significantly increased profitability of production systems.

Emerging perspectives in the gut-muscle axis: The gut microbiota and its metabolites as important modulators of meat quality

Animal breeding has made great genetic progress in increasing carcass weight and meat yield in recent decades. However, these improvements have come at the expense of meat quality. As the demand for meat quantity continues to rise, the meat industry faces the great challenge of maintaining and even increasing product quality. Recent research, including traditional statistical analyses and gut microbiota regulation research, has demonstrated that the gut microbiome exerts a considerable effect on meat quality, which has become increasingly intriguing in farm animals. Microbial metabolites play crucial roles as substrates or signalling factors to distant organs, influencing meat quality either beneficially or detrimentally. Interventions targeting the gut microbiota exhibit excellent potential as natural ways to foster the conversion of myofibres and promote intramuscular fat deposition. Here, we highlight the emerging roles of the gut microbiota in various dimensions of meat quality. We focus particularly on the effects of the gut microbiota and gut-derived molecules on muscle fibre metabolism and intramuscular fat deposition and attempt to summarize the potential underlying mechanisms.

Assessment of genomic breeding values and their accuracies for carcass traits in Jeju Black cattle using whole-genome SNP chip panels

The objective of the present study was to evaluate the breeding value and accuracy of genomic estimated breeding values (GEBVs) of carcass traits in Jeju Black cattle (JBC) using Hanwoo steers and JBC as a reference population using the single-trait animal model. Our research included genotype and phenotype information on 19,154 Hanwoo steers with 1097 JBC acting as the reference population. Likewise, the test population consisted of 418 genotyped JBC individuals with no phenotypic records for those carcass traits. For estimating the accuracy of GEBV, we divided the entire population into three groups. Hanwoo and JBC make up the first group; Hanwoo and JBC, who has both the genotype and phenotypic records, are referred to as the reference (training) population, and JBC, who lacks phenotypic information is referred to as the test (validation) population. The second group consists of the JBC (without phenotype) as the test population and Hanwoo as a reference population with phenotype and genotypic data. The only JBCs in the third group are those who have genotypic and phenotypic data on them as a reference population but no phenotypic data on them as a test population. The single-trait animal model was used in all three groups for statistical purposes. The reference populations estimated heritabilities for carcass weight (CWT), eye muscle area (EMA), backfat thickness (BF), and marbling score (MS) as 0.30, 0.26, 0.26, and 0.34 for the Hanwoo steer and 0.42, 0.27, 0.26, and 0.48 for JBC. The average accuracy for carcass traits in Group 1 was 0.80 for the Hanwoo and JBC reference population compared with 0.73 for the JBC test population. Although the average accuracy for carcass traits in Group 2 was 0.80, it was 0.80 for the Hanwoo reference population and only 0.56 for the JBC test population. The average accuracy for the JBC reference and test populations was 0.68 and 0.50, respectively, when they were included in the accuracy comparison without the Hanwoo reference population. Groups 1 and 2 used Hanwoo as reference population, which led to a better average accuracy; however, Group 3 only used the JBC reference and test population, which led to a lower average accuracy. This might be due to the fact that Group 3 used a smaller reference size than the group that came before it and that the genetic makeup of the Hanwoo and JBC breeds differed. The GEBV accuracy for MS was higher than that of other traits across all three analysis groups, followed by CWT, EMA, and BF, which may be partially explained by the MS traits' higher heritability. This study suggests that in order to achieve more accuracy, a large reference population particular to a breed should be established. Therefore, to increase the accuracy of GEBV prediction and the genetic benefit from genomic selection in JBC, individual reference breeds, and large populations are required.

Genomic heritability and correlation between carcass traits in Japanese Black cattle evaluated under different ceilings of relatedness among individuals

The investigation of carcass traits to produce meat with high efficiency has been in focus on Japanese Black cattle since 1972. To implement a successful breeding program in carcass production, a comprehensive understanding of genetic characteristics and relationships between the traits is of paramount importance. In this study, genomic heritability and genomic correlation between carcass traits, including carcass weight (CW), rib eye area (REA), rib thickness (RT), subcutaneous fat thickness (SFT), yield rate (YI), and beef marbling score (BMS) were estimated using the genomic data of 9,850 Japanese Black cattle (4,142 heifers and 5,708 steers). In addition, we investigated the effect of genetic relatedness degree on the estimation of genetic parameters of carcass traits in sub-populations created based on different GRM-cutoff values. Genome-based restricted maximum likelihood (GREML) analysis was applied to estimate genetic parameters. Using all animal data, the heritability values for carcass traits were estimated as moderate to relatively high magnitude, ranging from 0.338 to 0.509 with standard errors, ranging from 0.014 to 0.015. The genetic correlations were obtained low and negative between SFT and REA [-0.198 (0.034)] and between SFT and BMS [-0.096 (0.033)] traits, and high and negative between SFT and YI [-0.634 (0.022)]. REA trait was genetically highly correlated with YI and BMS [0.811 (0.012) and 0.625 (0.022), respectively]. In sub-populations created based on the genetic-relatedness ceiling, the heritability estimates ranged from 0.212 (0.131) to 0.647 (0.066). At the genetic-relatedness ceiling of 0.15, the correlation values between most traits with low genomic correlation were overestimated while the correlations between the traits with relatively moderate to high correlations, ranging from 0.380 to 0.811, were underestimated. The values were steady at the ceilings of 0.30-0.95 (sample size of 5,443-9,850) for most of the highly correlated traits. The results demonstrated that there is considerable genetic variation and also favorable genomic correlations between carcass traits. Therefore, the genetic improvement for the traits can be simultaneously attained through genomic selection. In addition, we observed that depending on the degree of relationship between individuals and sample size, the genomic heritability and correlation estimates for carcass traits may be different.

The study of "muscle eye" in bulls of Ukrainian black-spotted dairy-meat breed as a factor in improving the properties of meat products

The impact of age, live weight, and growth rate of the bulls of Ukrainian breeds on the area of “muscle eye” (cross-section of m. longissimus dorsi when the carcass is divided into front and rear between the 12th and 13th ribs) was studied. The correlation between the size of the “muscle eye” and the carcass's characteristics and the meat's qualitative indicators was also determined. The research was conducted on the bulls of Ukrainian black-and-white dairy (UBWDB) and Ukrainian meat (UMB) breeds. Living animals “muscle eye” area was determined with the ultrasonic analyser Emperor 860, after slaughter. It was found that UMB bulls have the area of “muscle eye” twice as big as their UBWDB peers. The “muscle eye” area increases when growing the cattle to 400 – 450 kg. In the future, it will be practically independent of the age and weight of the animals and remains stable. An increase in the average daily gains within the breed leads to an increase in the “muscle eye” area. The area of “muscle eye” has a weak negative connection (r = -0.193) with meat tenderness and dry matter content (r = -0.345) and a positive one with slaughter weight (r = 0.614) and slaughter yield (r = 0.653). Of the three parameters (length, depth, and area) of “muscle eye”, the greatest impact on the technological properties of meat has depth. Its increase has a negative connection with meat tenderness (r = -0.810) and moisture (r = -0.474), but it has a positive impact on the moisture retention capacity (r = 0.338) and weight of weighed portion after heat treatment. The obtained results can be used to clarify the optimal growing parameters of the bulls of Ukrainian black-and-white dairy and meat breeds for meat and determine the optimal age and live weight of the cattle slaughter.

Manifestation of living and post-slaughter traits of productivity in inbred and outbred bull calves of Ukrainian meat cattle breed

Selection in meat cattle herds requires caution due to the manifestation of inbred depression in traits that affect the economics of this livestock industry. This paper analyses the productivity of inbred and outbred bull calves of the Ukrainian meat cattle breed and justifies methods of pair selection in purebred herds with natural pairing. In bull calves, the growth of animals and traits of their meat productivity after slaughter were considered. Inbreeding was determined based on their pedigree. Inbred animals tended to have a growth rate of 10.2% from birth to 8 months of age. Afterwards, their average daily gain in live weight decreases sharply compared to outbred peers, who grow faster over a more extended period. From 8 to 18 months of age, it is probably (p >0.95) higher by 27.3% compared to inbred animals. Inbred bull calves have higher variability (Cv,%) in average daily gains. This indicates different adaptations to the environment during the suckling period and after weaning. Outbred animals tend to gain 2.3% of body weight at 12 months, 4.7 at 15 months, and 10.3% at 18 months. Its variability with age decreases by 7.4 points in inbred bull calves and 0.4 points in outbred ones, from 8 to 18 months. The inbred animals spent 29.5% more feed per kg of gain (p >0.95) than the outbred ones. Inbred bull calves vs outbred ones at 15 and 18 months of age tend to improve the expression of meat forms by 1.3 and 2.7%. They are relatively shorter and have a more rounded barrel. As a result, they have a shorter period of rapid growth. With the small size of the Ukrainian meat cattle population, one of the most important problems is reducing genetic variation in beef productivity traits and manifesting inbred depression in them. In purebred commercial herds, the mating of close animals should be avoided. To do this, an "order" for bulls should be made, and pairs should be selected without using inbreeding at different grades. Thus, outbred bull calves will reach live weight more quickly, spending less feed per growth unit, and have better basic slaughter traits.

Main regulatory factors of marbling level in beef cattle

The content of intramuscular fat (IMF), that determines marbling levels is considered as one of the vital factors influencing beef sensory quality including tenderness, juiciness, flavour and colour. The IMF formation in cattle commences around six months after conception, and continuously grows throughout the life of the animal. The accumulation of marbling is remarkably affected by genetic, sexual, nutritional and management factors. In this review, the adipogenesis and lipogenesis process regulated by various factors and genes during fetal and growing stages is briefly presented. We also discuss the findings of recent studies on the effects of breed, gene, heritability and gender on the marbling accumulation. Various research reported that feeding during pregnancy, concentrate to roughage ratios and the supplementation or restriction of vitamin A, C, and D are crucial nutritional factors affecting the formation and development of IMF. Castration and early weaning combined with high energy feeding are effective management strategies for improving the accumulation of IMF. Furthermore, age and weight at slaughter are also reviewed because they have significant effects on marbling levels. The combination of several factors could positively affect the improvement of the IMF deposition. Therefore, advanced strategies that simultaneously apply genetic, sexual, nutritional and management factors to achieve desired IMF content without detrimental impacts on feed efficiency in high-marbling beef production are essential.

Estimation of Genetic Correlations of Primal Cut Yields with Carcass Traits in Hanwoo Beef Cattle

Simple Summary

Recently, there is a growing interest in the genetic improvement of carcass merit in the Korean beef industry. Primal cut yields have been proposed to characterize the meat quality and quantity in beef cattle and are known to be genetically correlated with the carcass merit and premium prices. Hence, knowledge of genetic parameters is required to select the weight of primal cuts that may be used as the selection criteria for designing future breeding programs. This study aimed to estimate the heritability and genetic and phenotypic correlations of primal cut yields and carcass traits in Hanwoo cattle. All traits presented a medium to high heritability, which indicates a probable increase in their response to selection. In addition, moderate to highly favorable genetic correlations were found between the primal cut yields and carcass traits, such as the carcass weight and eye muscle area. Therefore, results suggested inclusion of primal cut traits as a selection objective in Hanwoo breeding programs to meet the growing demand for high quality products.

Abstract

This study was carried out to estimate the variance components, heritability, and genetic correlations between the carcass traits and primal cut yields in Hanwoo cattle. Carcass traits comprising 5622 records included back fat thickness (BFT), carcass weight (CW), eye muscle area (EMA), and marbling score (MS). The 10 primal cut yields from 3467 Hanwoo steers included the tenderloin (TLN), sirloin (SLN), striploin (STLN), chuck (CHK), brisket (BSK), top round (TRD), bottom round (BRD), rib (RB), shank (SK), and flank (FK). In addition, three composite traits were formed by combining primal cut yields as novel traits according to consumer preferences and market price: high-value cuts (HVC), medium-value cuts (MVC), and low-value cuts (LVC). Heritability estimates for the interest of traits were moderate to high, ranging from 0.21 ± 0.04 for CHK to 0.59 ± 0.05 for MS. Except genetic correlations between RB and other primal cut traits, favorable and moderate to high correlations were observed among the yields of primal cut that ranged from 0.38 ± 0.14 (CHK and FK) to 0.93 ± 0.01 (TRD and BRD). Moreover, the estimated genetic correlations of CW and EMA with primal cut yields and three composite traits were positive and moderate to strong, except for BFT, which was negative. These results indicate that genetic progress can be achieved for all traits, and selection to increase the yields of primal cuts can lead to considerable profitability in the Hanwoo beef industry.